Press-stud

ABSTRACT

A press-stud comprises a female element having a seat in which is accommodated a resiliently deformable anchoring member ( 22 ) which is to anchor a male element in a closed configuration of the stud. The anchoring member is a ring having a flattened cross-section with an inner edge ( 24 ) on which are defined substantially freely bending arcuate lips ( 29 ) which project in a cantilevered manner from a support wall of the female element ( 10 ) by not more than one third of the width of the flattened cross-section of the anchoring ring ( 22 ). Preferably, the press-stud has an overall height, in the closed configuration, which does not exceed 2.5 mm, and a ratio between the diameter and the height which is greater than 3.5.

The present invention relates to the field of press-studs.

The invention has been developed with particular regard to a press-studcomprising a female element having a seat for accommodating aresiliently deformable anchoring member which is to anchor a maleelement in a closed configuration of the stud.

Various press-studs of the type indicated above are known for satisfyingthe most varied market requirements. Press-studs are all the moreappreciated the better their hold while closed and the ease with whichthey can be opened. In addition, the best press-studs are very strongand maintain their coupling and uncoupling characteristics for a longtime, even after a very large number of opening and closing cycles.

Press-studs of the most common type have a male element comprising ahead which engages in the accommodating seat of the female element whereit is locked by a spring in the form of a split ring. An improved modelof a press-stud, developed by the present applicant and illustrated inthe patent EP 0855865, comprises a special spring which permits the useof a male element having a substantially flat head, which is appreciatedfrom the aesthetic point of view.

The object of the present invention is to improve the press-studs of theprior art, in particular by reducing the axial space requirement thereofas much as possible while at the same time ensuring optimumfunctionalities of good hold while closed, easy opening and strengthover time. A further object of the invention is to provide a simple andeconomical press-stud.

In order to achieve the objects indicated above, the invention relatesto a press-stud having the features indicated in the claims whichfollow.

The press-stud described here comprises a female element having a seatfor accommodating a resiliently deformable anchoring member which is toanchor a male element in a closed configuration of the stud, wherein theanchoring member is a ring having a flattened cross-section. The ringhas an inner edge on which are defined substantially freely bendingarcuate lips which project in a cantilevered manner from a support wallof the female element, preferably by not more than one third of thewidth of the flattened cross-section of the anchoring ring.

The lips are preferably defined by notches having a width which is muchsmaller than the length of the circumference of the inner edge of theflattened ring. Preferably, the depth of the notches is substantiallyequal to the cantilevered projection of the lips from the support wall.

Preferably, the notches are substantially U-shaped, and even morepreferably they are three in number, although they could be smaller innumber, for example two, or larger in number, for example four or five.The notches are preferably equidistant along the circumference of theinner edge of the flattened ring.

In the press-stud described, the anchoring ring is preferably held inthe female element by an annular covering strip. Preferably, the overallheight of the press-stud described, in an axial direction of insertionof the male element into the female element, in the closed configurationof the press-stud, does not exceed 2.5 mm. Preferably, in the studdescribed, the ratio between the diameter and the height in an axialdirection of insertion of the male element into the female element, inthe closed configuration, is greater than 3.5.

Further features and advantages will emerge from the following detaileddescription with reference to the appended drawings which are given byway of non-limiting example and in which:

FIG. 1 is a perspective view of an embodiment of the female element of apress-stud according to the present invention,

FIG. 2 is a cross-section through a male element of the press-studaccording to the present invention,

FIG. 3 is a cross-section through the female element of FIG. 1, and

FIG. 4 is a cross-section through another embodiment of the femaleelement of a press-stud according to the present invention.

Referring now to FIGS. 1 and 3, a press-stud according to one embodimentof the present invention comprises a female element 10 having a baseplate 12 with a central hole 14 of axis Z-Z which is to receive aconnecting member, for example a nail or rivet or another functionallysimilar element, for connecting the female element 10 to a substrate,for example a piece of fabric, cloth, leather, plastics material orother materials of various types.

The base plate 12 has an inclined peripheral edge 16 which continues ina flat manner to form a low annular step which defines a substantiallyplane annular support wall 18 having a circular peripheral edge 20 forcontaining an annular spring or resilient member 22 having asubstantially rectangular flattened cross-section. The resilient member22 can rest flat on the annular support wall 18 via a lower face 22 athereof, which is likewise substantially plane, in such a manner thatthe inner edge 24 of the resilient member 22 projects in a cantileveredmanner from the annular support wall 18 towards the inside of the femaleelement 10. As can be seen in FIG. 3, the cantilevered projection of theinner edge 24 of the resilient member 22 is very small, and preferablydoes not exceed approximately one third, and even more preferablyapproximately one quarter, of the width of the flattened cross-sectionof the annular member.

The outer edge 26 of the resilient member 22 is disposed alongside or inthe vicinity of the circular edge 20, so that the resilient member 22 issubstantially centred axially in the female element 10, preferably withsome small degree of clearance.

Radial notches or incuts 28, which are preferably equidistant and evenmore preferably three in number, are preferably formed on the inner edge24 of the resilient member 22. The notches 28 preferably have a U-shapein plan and a very small size compared with the overall dimensions ofthe resilient member 22. As can in fact be seen in FIG. 1, the notchesextend radially over a length which corresponds substantially to, or isslightly less than, the extent to which the inner edge 24 of theresilient member 22 projects in a cantilevered manner from the annularsupport wall 18. The width of the notches 28 is likewise very smallcompared with the overall circumference of the inner edge 24 of theresilient member, which is thus configured as a series of arcuateelongate lips 29, which are preferably three in number, although thisdoes constitute a limitation. This configuration of the resilient member22 promotes a good snap hold of the press-stud, and at the same timepermits a considerable reduction in the axial dimensions, that is tosay, in the direction of the axis Z-Z of the stud, because the bendingexcursion of the resilient member 22 in the direction Z-Z upon insertionof the male element of the stud is small in magnitude.

An annular cap 30 partially covers the upper face 22 b of the resilientmember 22 in order to hold it in position inside the female element 10.To that end, the annular cap 30 has an outer skirt 32 which wraps roundthe circular edge 20, being bent underneath it.

Overall, the female element 10 is very compact in the axial directionZ-Z, that is to say, the direction of insertion of a male element 40,which is illustrated in a preferred although non-limiting form in FIG.2. The male element 40 is produced substantially using a single piece ofbent sheet-metal which comprises an outer annular flange 42 from whichprojects a lateral wall 41 which is knurled, that is to say, shaped withan annular depression 43 which is to cooperate actively with the lips 29of the resilient member 22 of the female element 10. The lateral wall 41is terminated by a rounded end 44 which is connected by a small link 46to an inner wall 48 which ends in a base 50. Formed in the base 50 is acentral opening 52 which is to receive a connecting member, for examplea nail or rivet or another functionally similar element, for connectingthe male element 40 to a substrate, for example a piece of fabric,cloth, leather, plastics material or other materials of various types,to be connected to the corresponding substrate to which, as statedabove, the female element 10 of the press-stud according to theinvention is secured.

Another embodiment of a female element 60 of the present invention isillustrated in FIG. 4. Analogously to the female element describedabove, the female element 60 likewise has a base plate 62 having acentral hole 64 which is to receive a connecting member, for example anail or rivet or another functionally similar element, for connectingthe female element 60 to a substrate as mentioned above. Here too, anannular portion 66 of the base plate 62 is bent slightly to form a lowsubstantially flat annular step 68 having a circular edge 70 forcontaining an annular spring or resilient member 72 which is entirelyanalogous to the annular spring 22 described above.

In particular, the annular spring or resilient member 72 rests flat onthe annular step 68 with its substantially plane lower face 72 a, sothat its inner edge 74 projects in a cantilevered manner beyond thestep, as described above, while its preferably circular outer edge 76 isdisposed substantially alongside the circular edge 70 with play or inthe vicinity thereof. Radial notches or incuts 78, which are preferablyequidistant and even more preferably three in number and whichcorrespond to the notches 28 described above and have a similar functionand features, are preferably formed on the inner edge 74 of the annularspring 72.

Unlike the female element 10 described above, the female element 60 doesnot have a separate cap for holding the resilient member 72 inside itbut, instead, the circular edge 70 is extended and bent over theresilient member 72 to form an annular rim 80 for containing theresilient member 72. In particular, the annular rim 80 is disposedalongside the upper face 72 b of the resilient member 72, but withoutcompressing or crushing it.

A press-stud produced in accordance with the invention permitsminimization of the axial space requirement along the axis Z-Z, as wellas of its weight. This is particularly advantageous when used forlight-weight garments, for example of silk, or in cases where thethickness of the stud could prove troublesome, such as in the case ofclosures for purses, wallets, pillow-cases, etc., but of course the usesof such a stud are varied and are not limited to those given by way ofexample.

In order to produce a press-stud having reduced axial dimensions, whileensuring its correct functioning, solid strength and excellent snaphold, with the aim of manufacturing the metal component parts thereof bythe deformation of pieces of sheet-metal, rather than by the far moreexpensive methods of turning or die-casting, it has been found that theoptimum thickness of the sheet-metal is preferably from 0.3 to 0.4 mm,while the overall height of the knurled male element 40 in the directionof the axis Z-Z is preferably from 1.9 to 2.0 mm. Those features providefor an overall size of the press-stud according to the presentinvention, in the closed configuration with the male element connectedto the female element, of preferably approximately from 2.3 to 2.5 mm,which, to the applicant's knowledge, is smaller than the axial spacerequirement of any known type of press-stud having a metal body.

In order to reduce even further the axial dimensions of the press-studof the present invention, with all of the other features remaining thesame, it is possible to use a spring or resilient member which islikewise composed of sheet-metal having high-grade flexibilitycharacteristics, for example piano wire. Thus, the cross-section of theresilient member of the present invention, which is always characterizedby being flattened, may have an extremely small thickness in the axialdirection Z-Z of approximately a few tenths of a millimetre. In the caseof a resilient member of plastics material, its dimension in the axialdirection Z-Z may in any case be less than 1.0 mm, adopting theconfiguration features of the present invention.

The press-stud of the present invention is also characterized in that,as clearly visible in the appended Figures, the ratio between theoverall diameter and its height is preferably greater than 3.5.

The system for securing the male and female elements to the respectivesubstrates could be of a type other than that illustrated and could beobtained, for example, by stitching or, in order to reduce the spacerequirement even further, also by adhesive bonding. In such cases, it isnot necessary for the male and female elements of the press-stud to havethe hole and the central opening indicated by the reference numerals 14,64 and 52, respectively, and shown in FIGS. 2 and 3.

The materials used may also be of a type other than that illustratedbecause it is not necessary to use sheet-metal for the production of thepress-stud of this invention, it also being possible to use plasticsmaterials or materials of another type, alone or in combination withmetal materials. Naturally, the principle of the invention remaining thesame, the forms of embodiment and details of construction may be variedwidely with respect to those described and illustrated, without therebydeparting from the scope of the present invention.

1. A press-stud, comprising a female element having a seat foraccommodating a resiliently deformable anchoring member which is toanchor a male element in a closed configuration of the stud, wherein theanchoring member is a ring having a flattened cross-section (22, 72)with an inner edge (24, 74) on which are defined substantially freelybending arcuate lips (29) which project in a cantilevered manner from asupport wall (18, 68) of the female element (10, 60) by not more thanone third of the width of the flattened cross-section of the anchoringring (22, 72).
 2. A press-stud according to claim 1, wherein the lipsare defined by notches (28, 78) having a width much smaller than thelength of the circumference of the inner edge (24, 74) of the flattenedring.
 3. A press-stud according to claim 2, wherein the depth of thenotches (28, 78) is substantially equal to the cantilevered projectionof the lips (29) from the support wall (18, 68).
 4. A press-studaccording to claim 2, wherein the notches (28, 78) are substantiallyU-shaped.
 5. A press-stud according to claim 2, comprising at leastthree notches (28, 78).
 6. A press-stud according to claim 2, whereinthe notches (28, 78) are equidistant along the circumference of theinner edge (24, 74) of the flattened ring.
 7. A press-stud according toclaim 1, wherein the anchoring ring (22, 72) is held in the femaleelement by an annular covering strip (30, 80).
 8. A press-stud accordingto claim 1, having an overall height in an axial direction (Z-Z) ofinsertion of the male element (40) into the female element (10, 60), inthe closed configuration, which does not exceed 2.5 mm.
 9. A press-studaccording to claim 1, wherein the ratio between the diameter and theheight in an axial direction (Z-Z) of insertion of the male element (40)into the female element (10, 60), in the closed configuration, isgreater than 3.5.